Limber Pipeline Application

Description

A flexible front end to pipelines in Sequencescape.

User Requirements

• Used on laboratory instrument machines often running older browser versions due to vendor and network limitations. The user-agent strings extracted from the nginx access logs of August 2024 indicate that the the oldest browser suspected of using Limber is Chrome 65. This means that the minified code served to browsers should be compatible with ECMAScript 2018. Please see the Limber page on Confluence for more information.

Initial Setup (using Docker)

Docker provides all the dependencies needed by Limber, so there is less to install on your machine. It can make development harder though, so it might be preferable to use a native installation (see below) if that is possible on your machine. The only dependency that isn't provided is Sequencescape, so please ensure you have that running on port 3000 on your localhost before attempting to run Limber in Docker.

You must have Docker Desktop installed on your machine. Then the only command you should need to run is:

docker compose up

Variations on this command include:

• docker compose up -d which starts the container as a background task (freeing up the terminal). You can then use docker compose down to turn it off again.
• GENERATE_CONFIG=false docker compose up which will avoid running the config:generate rake task as Limber is started.
• PRECOMPILE_ASSETS=false docker compose up which will avoid precompiling the assets as Limber is started.
• docker compose up --build which forces a rebuild of the Docker image if your changes to the Dockerfile or related scripts don't seem to be taking effect.

Limber should be accessible via http://localhost:3001.

Initial Setup (using native installation)

Because Limber is only a frontend that relies on SequenceScape as a backend, SequenceScape and it's jobs must be started first. SequenceScape will work standalone without Limber, Limber won't run without SequenceScape.

Note that this will require SequenceScape to have already been setup before

1. The post deploy task will generate required records for Record Loader if they haven't been already. In a Sequencescape terminal, perform the post deploy actions:

   bundle exec rake application:post_deploy

2. In the same terminal, start the local server (will start on port 3000):

   bundle exec rails s

3. Open a second SequenceScape terminal, start the delayed job processor. This ensures that background processes are being handled:

   bundle exec rake jobs:work

All the setup for SequenceScape will have been completed. This should be done first as Limber will rely on some of the data generated previosly.

Only one terminal for Limber is needed (unless running the integration suite)

1. In Limber, ensure the appropriate version of Ruby is installed. The command here is for rbenv but you may want to use a different Ruby version manager:

   rbenv install

2. In Limber, make the Bundler gem install the dependencies for this project:

   bundle install

3. In Limber, install the yarn dependencies:

   nvm use  # If you manage node environments with nvm
   yarn install

4. In Limber, connect to Sequencescape to configure required data. This requires SequenceScape to be running, which will have been done in the previous steps:

   bundle exec rake config:generate

5. In Limber, start the local server (will start on port 3001):

   bundle exec rails s

6. In a second Limber terminal, start the Vite development server for faster development of frontend resources (will start on port 3036):

   yarn dev

Linting and formatting

Linting and formatting are provided by rubocop, prettier and Eslint. I strongly recommend checking out editor integrations. Also, using lefthook will help ensure that only valid files are committed.

# Run rubocop
bundle exec rubocop
# Run rubocop with safe autofixes
bundle exec rubocop -a
# ESlint
yarn lint
# Check prettier formatting
yarn prettier --check .
# Fix prettier formatting
yarn prettier --write .

Troubleshooting

ViteRuby::MissingEntrypointError in Search#new

If you see an error like this:

Showing /code/app/views/layouts/application.html.erb where line #10 raised:

Vite Ruby can't find entrypoints/application.css in the manifests.

Possible causes:
  - The last build failed. Try running `bin/vite build --clear --mode=development` manually and check for errors.

Errors:
  /code/node_modules/rollup/dist/native.js:59
  		throw new Error(

Then you may need to run bin/vite build --clear --mode=development as suggested, and reload the page.

Alternatively, run ./compile_build.sh to compile the build files or run yarn dev to start the Vite development server.

Changes not updating

If during development changes do not seem to be taking effect, try:

• Restart the application:
• Destroy and recreate the Docker container docker compose down && GENERATE_CONFIG=false docker compose up -d
• Rebuild the Docker image, particularly useful for changing dependencies
• Clobber local resources rails assets:clobber

Note about the remainder of this document

The rest of the sections shown here were written for and apply to the native installation, but can also be used in the Docker container if required. In order to use Docker, it's probably best to create a shell in the running container. Assuming you started the container via docker compose you can access the shell using:

docker exec -ti limber_limber_1 bash

If the container isn't recognised, check the container name (right hand column) using docker ps --all, ensure it's up/running and substitute the name into the above command in place of limber_limber_1.

Docs

In addition to the externally hosted YARD docs, you can also run a local server:

yard server -r --gems -m limber

You can then access the Limber documentation through: http://localhost:8808/docs/limber Yard will also try and document the installed gems: http://localhost:8808/docs

Configuring pipelines

{file:docs/configuring_new_pipelines.md Configuring new pipelines}

Running Specs

RSpec

Ruby unit and feature tests:

bundle exec rspec

Vitest

JavaScript unit tests:

yarn test
yarn test "path/to/file" -t "name of the test"

Writing specs

There are a few tools available to assist with writing specs:

Factory Bot

• Strategies: You can use json :factory_name to generate the json that the API is expected to receive. This is very useful for mocking web responses. The association strategy is used for building nested json, it will usually only be used as part of other factories.

• Traits:

  • api_object: Ensures that lots of the shared behaviour, like actions and uuids are generated automatically barcoded: Automatically ensures that barcode is populated with the correct hash, and calculates human and machine barcodes
  • build: Returns an actual object, as though already found via the api. Useful for unit tests

• Helpers: with_has_many_associations and with_belongs_to_associations can be used in factories to set up the relevant json. They won't actually mock up the relevant requests, but ensure that things like actions are defined so that the api knows where to find them.

Request stubbing for the Sequencescape v1 API

Request stubs are provided by webmock. Two helper methods will assist with the majority of mocking requests to the api, stub_api_get and stub_api_post. See spec/support/api_url_helper.rb for details.

Note: Due to the way the api functions, the factories don't yet support nested associations.

Request stubbing for the Sequencescape v2 API

The V2 API uses JsonApiClient::Resource sub-classes to represent the records in memory. Generally these are quite dynamic so you don't need to explicitly specify every property the API will respond with. The base class also provides us with methods that are familiar to Rails for finding one or more records that match criteria. So to stub the API, the easiest thing to do is to get FactoryBot to make up resources using the specific resource sub-class for the V2 API, and then mock the calls to those lookup methods. Many of these have already been done for you in spec/support/api_url_helper.rb such as stub_v2_study and stub_v2_tag_layout_templates which sets up the find method for studies by name and the all method for tag layout templates, respectively. However there's also stub_api_v2_post, stub_api_v2_patch and stub_api_v2_save which ensures that any calls to the create, update and the save method for resources of a particular type are expected and give a return value. If none of the existing method suit your needs, you should add new ones.

FactoryBot is not mocking my related resources correctly

Nested relationships, such as Wells inside a Plate, the resource should indicate this with keywords like has_one, has_many, belongs_to, etc. See the json_api_client repository for this topic and more. However, FactoryBot does not get on well with some of these relationship methods and will not mock them properly using standard FactoryBot definitions.

If you find that FactoryBot is not giving you the expected resource for a related record, you can inject the related resource directly into the JsonApiClient::Resource's cache of relationships. To do that, define the related resource as a transient variable and use an after(:build) block to assign the resource to the _cached_relationship method. For example, where the Resource might be defined as the following class:

class Sequencescape::Api::V2::RootRecord < JsonApiClient::Resource
  has_one :related_thing
end

You might expect to be able to use FactoryBot in the following way:

FactoryBot.define do
  factory :root_record, class: Sequencescape::Api::V2::RootRecord do
    skip_create

    related_thing { create :related_thing }
  end
end

But the related thing will not be the one you defined to be generated by another factory. It appears the has_one method in the resource over-rides the mocked value and you get an empty record back instead. So, instead, you should create the related_thing record as a transient and assign it to the root_record in an after(:build) block as shown here.

FactoryBot.define do
  factory :root_record, class: Sequencescape::Api::V2::RootRecord do
    skip_create

    transient { related_thing { create :v2_tag_group_with_tags } }

    after(:build) do |record, factory|
      record._cached_relationship(:related_thing) { factory.related_thing } if factory.related_thing
    end
  end
end

Feature debugging

To help with debugging feature specs, temporarily comment out the line options.add_argument('--headless') in spec/spec_helper.rb. This will allow you to see the browser as the tests run. To pause the execution at certain point, possibly before an expected failure, insert binding.pry at the appropriate place in the spec.

To save a screenshot of the browser, insert the line below into the spec.

save_screenshot("#{Time.now.iso8601}.png")

Screenshots will be saved to tmp/capybara/.

Lefthook

Lefthook is a git-hook manager that will ensure staged files are linted before committing.

You can install it either via homebrew brew install Arkweid/lefthook/lefthook or rubygems gem install lefthook

You'll then need to initialize it for each repository you wish to track lefthook install

Hooks will run automatically on commit, but you can test them with: lefthook run pre-commit

In addition you can also run lefthook run fix to run the auto-fixers on staged files only. Note that after doing this you will still need to stage the fixes before committing. I'd love to be able to automate this, but haven't discovered a solution that maintains the ability to partially stage a file, and doesn't involve running the linters directly on files in the .git folder.